Magnum from Munich writes in, and I’m too tired to do anything more involved than copying/pasting his email:
Finally the stem is slammed. How? Changing the FSA Orbit supertall CX bearing cover for the flattest one, code H2051A. So for those with a FSA Orbit headset with a tall bearing cover, remove it and check that on the the the rubber seal is written MS073-11/8, then order the FSA bearing cove, item No H2051A.
So, there you have it. If you’ve got an FSA Orbit headset, there is hope!